Back to AI Flashcard MakerAnatomy and Physiology /A-Level PE AQA Cardiovascular System Part 2
A-Level PE AQA Cardiovascular System Part 2
This deck covers key concepts of the cardiovascular system, including Starling's law, venous return mechanisms, the Bohr Shift, nervous system roles, and circulation types.
What does more blood pumped back to the heart mean? What law does this prove?
It means more blood is pumped out which increases stroke volume. It proves Starling’s law
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Key Terms
Term
Definition
What does more blood pumped back to the heart mean? What law does this prove?
It means more blood is pumped out which increases stroke volume. It proves Starling’s law
What is Starling’s law?
When venous return increase there is a greater diastolic filling of the heart. Cardiac muscles are then stretched. This allows for greater force of co...
What are the venous return mechanisms?
. Skeletal muscle pump . Respiratory pump . Pocket valves
How does the skeletal muscle aid venous return?
The muscles contract and relax meaning they change shape. This will cause the muscles to press on nearby veins and cause a pumping effect squeezing bl...
How does the respiratory pump aid venous return?
The muscles contract and relax during breathing in and out. This causes there to be a pressure change to occur in the thoracic and abdominal cavities....
How do pocket valves aid venous return?
These valves prevent blood flowing back and close once blood has passed through
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| Term | Definition |
|---|---|
What does more blood pumped back to the heart mean? What law does this prove? | It means more blood is pumped out which increases stroke volume. It proves Starling’s law |
What is Starling’s law? | When venous return increase there is a greater diastolic filling of the heart. Cardiac muscles are then stretched. This allows for greater force of contraction causing an increased ejection fraction |
What are the venous return mechanisms? | . Skeletal muscle pump . Respiratory pump . Pocket valves |
How does the skeletal muscle aid venous return? | The muscles contract and relax meaning they change shape. This will cause the muscles to press on nearby veins and cause a pumping effect squeezing blood to heart |
How does the respiratory pump aid venous return? | The muscles contract and relax during breathing in and out. This causes there to be a pressure change to occur in the thoracic and abdominal cavities. Due to this pressure change it compresses the nearby veins and assist blood return to heart |
How do pocket valves aid venous return? | These valves prevent blood flowing back and close once blood has passed through |
What other mechanisms of venous return are there? | Gravity because blood from upper body returns to heart |
Why is a cool down performed? | Because it keeps the skeletal and respiratory pump working which therefore prevents blood pooling |
What happens to the venous return if systolic pressure increases? | If systolic pressure increases then venous return also increases |
What happens to venous return if systolic pressure decreases? | If systolic pressure decreases then venous return also decreases |
Why does the Bohr Shift shift to the right? | Because when muscles require more oxygen the dissociation of O2 from haemoglobin in the blood capillaries to the muscle tissue occurs more readily and this results in more oxygen being available for use by the working muscles |
What are the three factors responsible for the increase in the dissociation of Oxygen from haemoglobin? | . An increase in blood temperature . An increase in partial pressure of CO2 . pH |
How does an increase in blood temperature increase dissociation of oxygen from haemoglobin? | Blood and muscle temp increase during exercise so oxygen will dissociate from haemoglobin more readily |
How does an increase in partial pressure of carbon dioxide increase dissociation of oxygen from haemoglobin? | Level of blood carbon dioxide rises during exercise so oxygen dissociates faster from haemoglobin |
How does an decrease in blood pH increase dissociation of oxygen from haemoglobin? | More carbon dioxide will lower the pH in the blood. A drop in blood pH will cause oxygen to dissociate from haemoglobin more quickly |
What is the sympathetic nervous system? | A part of the autonomic nervous system that speeds up heart rate |
What is the parasympathetic nervous system? | A part of the autonomic nervous system that decreases heart rate |
What are the cardiac control centres stimulated by? | Chemoreceptors; Baroreceptors; Proprioceptors |
What are chemoreceptors? | Tiny structures in the carotid arteries and aortic arch that detect changes in blood acidity caused by an increase or decrease in the concentration of carbon dioxide |
What are baroreceptors? | Special senses in tissues in the aortic arch, carotid sinus, heart and pulmonary vessels that respond to changes in blood pressure to either increase or decrease heart rate |
What are proprioreceptors? | Sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement |
What is adrenaline? | A stress hormone that is released by the sympathetic nerves and cardiac nerves during exercise, which causes an increase in heart rate |
What is ejection fraction? | The percentage of blood pumped up by the left ventricle per beat |
What is atherosclerosis? | Occurs when arteries harden and narrow as they become clogged up by fatty deposits |
What can cause atherosclerosis? | High blood pressure, high levels of cholesterol, lack of exercise and smoking |
What is atheroma? | A fatty deposit found in the inner lining of an artery |
What is angina? | Chest pain that occurs when the blood supply through the coronary arteries to the muscles of the heart is restricted |
What are the two types of circulation? | Pulmonary and systemic |
What is pulmonary circulation? | Deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart |
What is systemic circulation? | Oxygenated blood to the body from the heart, and then the return of deoxygenated blood from the body to the heart |
What is blood pressure? | It is the force exerted by the blood against the blood vessel wall, and is often referred to as: blood flow x resistance |
What is systolic pressure? | The pressure in the arteries when the ventricles are contracting |
What is diastolic pressure? | The pressure in the arteries when the ventricles are relaxing |
What are blood pressure and blood flow controlled by? | The vasomotor centre? |
How does the vasomotor centre redistribute bloodflow? | Through vasodilation and vasoconstriction |
What is vasodilation? | It is when the blood vessel widens to increase blood flow into the capillaries |
What is vasoconstriction? | It is when the blood vessel narrows to decrease blood flow |
How does vasodilation and vasoconstriction work during exercise? | During exercise, more oxygen is needed at working muscles, so vasodilation will occur in the arterioles supplying these muscles, increasing blood flow, and bringing in the much-needed oxygen, whereas vasoconstriction will occur in the arterioles supplying non-essential organs, such as the intestines and liver |
What is the vascular shunt mechanism? | The redirecting of blood flow to the areas where it is most needed |